To create a new repository, you need to use a new web interface at http://savannah.gnu.org/new/ [edit: this interface is now default, so just go to http://savannah.gnu.org/] and go to your project administration ("Main -> Select Features"). This is the next version of the web interface, with little user-visible changes but with cleaned-up code. It's currently in test so please tell us if you spot a remaining bug or a warning :)